Something happened to the aircraft performance (Mooney)

First flight with the new SU 5. Something has affected aircraft performance (at least on my Carenado Mooney). At the start of my descent (VFR flight), I cut down throttle all the way to 1/4 and the aircraft settled on a vertical speed of -150 fpm after I trimmed the nose up a little bit. IAS was down to 120 knots. This doesn't sound right. Before the update, if I cut throttle to 1/4 I would have to trim the aircraft nose up quite a bit to maintain such a slow descent, and I would soon get into the white arc (flap range).